Uba7^tm1Dez

Exon 14 encodes the active site for this enzyme that is responsible for activating ISG15 conjugation activity. LoxP sites were inserted upstream of exon 14 and downstream of exon 18. A Frt- and loxP- flanked neomycin resistance cassette was also inserted downstream of exon 18. Correct targeting was confirmed by Southern blotting. Splenocytes and thymocytes from homozygotes that were treated with IFN-beta expressed a larger mRNA transcript than controls due to the neomycin insertion. Tissue extracts from homozygote mice failed to demonstrate conjugating activity between ISG15 and larger protein complexes (i.e. no ISGylation activity). (J:144149)